5 files changed, 36 insertions, 38 deletions

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs b/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
index 478aeab..696c4bd 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
@@ -198,7 +198,8 @@ public sealed class BSCharacter : BSPhysObject
             // TODO: Decide if the step parameters should be changed depending on the avatar's
             //     state (flying, colliding, ...). There is code in ODE to do this.
 
-            OMV.Vector3 stepVelocity = _velocityMotor.Step(timeStep);
+            _velocityMotor.Step(timeStep);
+            OMV.Vector3 stepVelocity = _velocityMotor.CurrentValue;
 
             // If falling, we keep the world's downward vector no matter what the other axis specify.
             if (!Flying && !IsColliding)
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs b/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
index f2c7cec..7c9b83b 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
@@ -957,39 +957,25 @@ namespace OpenSim.Region.Physics.BulletSPlugin
 
         public void ComputeLinearVelocity(float pTimestep)
         {
-            Vector3 linearMotorStep = m_linearMotor.Step(pTimestep);
+            // Step the motor from the current value. Get the correction needed this step.
+            Vector3 currentVel = VehicleVelocity * Quaternion.Inverse(VehicleOrientation);
+            Vector3 linearMotorCorrection = m_linearMotor.Step(pTimestep, currentVel);
 
-            // The movement computed in the linear motor is relative to the vehicle
-            //     coordinates. Rotate the movement to world coordinates.
-            Vector3 linearMotorVelocity = linearMotorStep * VehicleOrientation;
+            // Motor is vehicle coordinates. Rotate it to world coordinates
+            Vector3 linearMotorVelocity = linearMotorCorrection * VehicleOrientation;
 
-            // If we're a ground vehicle, don't loose any Z action (like gravity acceleration).
-            float mixFactor = 1f;   // 1 means use all linear motor Z value, 0 means use all existing Z
+            // If we're a ground vehicle, don't add any upward Z movement
             if ((m_flags & VehicleFlag.LIMIT_MOTOR_UP) != 0)
             {
-                if (!Prim.IsColliding)
-                {
-                    // If a ground vehicle and not on the ground, I want gravity effect
-                    mixFactor = 0.2f;
-                }
-            }
-            else
-            {
-                // I'm not a ground vehicle but don't totally loose the effect of the environment
-                mixFactor = 0.8f;
+                if (linearMotorVelocity.Z > 0f)
+                    linearMotorVelocity.Z = 0f;
             }
-            linearMotorVelocity.Z = mixFactor * linearMotorVelocity.Z + (1f - mixFactor) * VehicleVelocity.Z;
-
-            // What we want to contribute to the vehicle's existing velocity
-            Vector3 linearMotorForce = linearMotorVelocity - VehicleVelocity;
-
-            // Act against the inertia of the vehicle
-            linearMotorForce *= m_vehicleMass;
 
-            VehicleAddForceImpulse(linearMotorForce * pTimestep);
+            // Add this correction to the velocity to make it faster/slower.
+            VehicleVelocity += linearMotorVelocity;
 
-            VDetailLog("{0},  MoveLinear,velocity,vehVel={1},step={2},stepVel={3},mix={4},force={5}",
-                        Prim.LocalID, VehicleVelocity, linearMotorStep, linearMotorVelocity, mixFactor, linearMotorForce);
+            VDetailLog("{0},  MoveLinear,velocity,vehVel={1},correction={2},force={3}",
+                        Prim.LocalID, VehicleVelocity, linearMotorCorrection, linearMotorVelocity);
         }
 
         public void ComputeLinearTerrainHeightCorrection(float pTimestep)
@@ -1204,6 +1190,7 @@ namespace OpenSim.Region.Physics.BulletSPlugin
         {
             // The user wants this many radians per second angular change?
             Vector3 angularMotorContribution = m_angularMotor.Step(pTimestep);
+            angularMotorContribution = m_angularMotor.CurrentValue;
 
             // ==================================================================
             // From http://wiki.secondlife.com/wiki/LlSetVehicleFlags :
@@ -1234,7 +1221,7 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                                     + deflectionContribution
                                     + bankingContribution;
 
-            // Add of the above computation are made relative to vehicle coordinates.
+            // All of the above computation are made relative to vehicle coordinates.
             // Convert to world coordinates.
             m_lastAngularVelocity *= VehicleOrientation;
 
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSMotors.cs b/OpenSim/Region/Physics/BulletSPlugin/BSMotors.cs
index 6d0db2e..82fd2d2 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSMotors.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSMotors.cs
@@ -138,7 +138,8 @@ public class BSVMotor : BSMotor
         CurrentValue = TargetValue = Vector3.Zero;
     }
 
-    // Compute the next step and return the new current value
+    // Compute the next step and return the new current value.
+    // Returns the correction needed to move 'current' to 'target'.
     public virtual Vector3 Step(float timeStep)
     {
         if (!Enabled) return TargetValue;
@@ -150,7 +151,7 @@ public class BSVMotor : BSMotor
         Vector3 error = TargetValue - CurrentValue;
         if (!ErrorIsZero(error))
         {
-            correction = Step(timeStep, error);
+            correction = StepError(timeStep, error);
 
             CurrentValue += correction;
 
@@ -187,14 +188,20 @@ public class BSVMotor : BSMotor
         else
         {
             // Difference between what we have and target is small. Motor is done.
-            CurrentValue = TargetValue;
+            CurrentValue = TargetValue = Vector3.Zero;
             MDetailLog("{0},  BSVMotor.Step,zero,{1},origTgt={2},origCurr={3},ret={4}",
                         BSScene.DetailLogZero, UseName, origCurrVal, origTarget, CurrentValue);
         }
 
-        return CurrentValue;
+        return correction;
+    }
+    // version of step that sets the current value before doing the step
+    public virtual Vector3 Step(float timeStep, Vector3 current)
+    {
+        CurrentValue = current;
+        return Step(timeStep);
     }
-    public virtual Vector3 Step(float timeStep, Vector3 error)
+    public virtual Vector3 StepError(float timeStep, Vector3 error)
     {
         if (!Enabled) return Vector3.Zero;
 
@@ -304,7 +311,7 @@ public class BSFMotor : BSMotor
         float error = TargetValue - CurrentValue;
         if (!ErrorIsZero(error))
         {
-            correction = Step(timeStep, error);
+            correction = StepError(timeStep, error);
 
             CurrentValue += correction;
 
@@ -347,7 +354,7 @@ public class BSFMotor : BSMotor
         return CurrentValue;
     }
 
-    public virtual float Step(float timeStep, float error)
+    public virtual float StepError(float timeStep, float error)
     {
         if (!Enabled) return 0f;
 
@@ -440,8 +447,8 @@ public class BSPIDVMotor : BSVMotor
         }
     }
 
-    // Ignore Current and Target Values and just advance the PID computation on this error.
-    public override Vector3 Step(float timeStep, Vector3 error)
+    // Advance the PID computation on this error.
+    public override Vector3 StepError(float timeStep, Vector3 error)
     {
         if (!Enabled) return Vector3.Zero;
 
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
index aaa6fe5..22afdc9 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
@@ -1082,7 +1082,7 @@ public sealed class BSPrim : BSPhysObject
                     OMV.Vector3 origPosition = RawPosition;     // DEBUG DEBUG (for printout below)
 
                     // 'movePosition' is where we'd like the prim to be at this moment.
-                    OMV.Vector3 movePosition = _targetMotor.Step(timeStep);
+                    OMV.Vector3 movePosition = RawPosition + _targetMotor.Step(timeStep);
 
                     // If we are very close to our target, turn off the movement motor.
                     if (_targetMotor.ErrorIsZero())
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt b/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
index 9bfec19..23b7ca8 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
+++ b/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
@@ -74,7 +74,10 @@ Incorporate inter-relationship of angular corrections. For instance, angularDefl
 GENERAL TODO LIST:
 =================================================
 Implement llSetPhysicalMaterial.
+        extend it with Center-of-mass, rolling friction, density
 Implement llSetForceAndTorque.
+Change BSPrim.moveToTarget to used forces rather than changing position
+        Changing position allows one to move through walls
 Implement an avatar mesh shape. The Bullet capsule is way too limited.
         Consider just hand creating a vertex/index array in a new BSShapeAvatar.
 Verify/fix phantom, volume-detect objects do not fall to infinity. Should stop at terrain.